Huge volumes of contaminated waste waters are produced daily as a result of industrial processing. Such waste water contains one or more components which may be sufficiently valuable to merit recovery or hazardous to living organisms in the environment, either directly or indirectly. Some examples of contaminants which are sufficiently valuable to merit recovery include silver, gold, and platinum. There are a multitude of different hazardous components, including, for example, radioactive materials, metals, inorganic chemicals and organic chemicals. Examples of sources of serious contamination of waste water include organic chemicals such as pesticides and solvents and residues from electroplating processes, metal mining or refining processes, paint manufacturing, petroleum refining, pharmaceutical production and the production of batteries.
The disposal of radioactive waste water presents a serious burden to power companies and other agencies having to deal with it. Some disposal techniques involve the fixation of the radioactive waste water into a solid form prior to disposal and require that there is little or no bleeding of the water borne radioactive material and/or leaching of radioactive material from the fixed form. Various attempts have been made to accomplish this task, but the results have proven to be undesirable for one or more reasons. Some require the use of cement or other inorganic fixing media which will only fix a minor portion of waste water as compared to the amount of fixing medium required. Others are extremely expensive to use, complicated, and not necessarily effective. Some methods utilize polymeric materials which polymerize in the presence of water to encapsulate or otherwise entrap a certain amount of waste water, but some of the resultant polymers tend to bleed or permit leaching of radioactive materials.
The following references, illustrative of the prior art, disclose various methods of fixing or otherwise restraining the mobility of radioactive hazardous waste water or other waste materials and various related matters.
U.S. Pat. No. 4,156,658 discloses a method for fixing radioactive ions in porous media by injecting into the porous media water-soluble organic monomers which are polymerizable to gel structures with ionic exchange sites.
U.S. Pat. No. 4,077,901 discloses a method of encapsulating toxic waste materials in a vinyl ester resin or an unsaturated polyester by curing the resin under conditions which maintain the integrity of the encapsulating material.
U.S. Pat. No. 3,298,960 discloses a method of disposing of waste solutions by adding a gelling agent such as sodium silicate or formaldehyde to a metal cleaning waste solution which may contain hydrazine and ethylenediaminetetracetic acid or other dissolved hazardous components to provide a solid, vibrant gel.
U.S. Pat. No. 4,167,491 discloses a method of disposing of wet radioactive waste material by combining it with a hydrophilic resin such as urea-formaldehyde dispersion to provide a solid mass with the radioactive waste component distributed therein.
U.S. Pat. No. 4,148,745 discloses mixing radioactive material with phosphoric acid ester and polyvinyl chloride to provide a non-volatile mass which does not flow.
U.S. Pat. Nos. 4,056,362 and 4,168,243 disclose a system for disposing of radioactive waste material by solidifying the liquid components with a water extendable polymer consisting of an aqueous suspension of urea formaldehyde.
U.S. Pat. No. 4,010,108 discloses a method of disposing of wet radioactive material by combining the material with a hydrophilic resin, preferably urea formaldehyde dispersion.
U.S. Pat. No. 4,131,563 discloses a process for preparing toxic waste containing radioactive or toxic substances for safe handling by mixing the same with a polymerizable mixture consisting essentially of monovinyl and polyvinyl compounds and polymerization catalysts to convert the mixture to a solid block.
U.S. Pat. No. 4,118,354 discloses a polyurethane hydrogel which may be prepared by polymerizing polyurethane prepolymers in the presence of liquid wastes which may contain noxious materials and radioactive substances to prevent such materials from being scattered.
U.S. Pat. No. 3,719,050 discloses a soil stabilization method comprising injecting polyurethane prepolymer, alone or in a mixture with water, to the soil and reacting the prepolymer with water in soil to solidify the same.
German Offenlegungsschrift No. 26 52 957 discloses a method of solidifying radioactive waste by mixing with formaldehyde urea prepolymer in the presence of a hardener and a chelating agent.
Japanese Kokai No. 73 23,690, Mar. 27, 1973, discloses a process of eliminating heavy metal ions from waste water by treating the water with a copolymer of alpha amino acids and their salts and acrylamide and methacrylamide.
While some of the methods described above may have some merit, many are deficient in one or more respects. Some produce an encapsulating polymeric structure which provides a shell around a body of hazardous waste water which is prone to rupture and thus cause bleeding of the hazardous material contained therein. Some do not have adequate cohesive strength and thus are subject to rupture, fragmentation, or other deficiencies attendant with the low structural integrity. Some will not cure except at high temperatures and others cure too rapidly for convenient handling. Still others are subject to leaching or hazardous material upon exposure to ground water.